Modeling of micro aluminum particle combustion in multiple oxidizers

Prediction of combustion characteristics of aluminum particle is of great significance for a variety of propulsion and power systems to achieve optimal energy release within a limited residence time. In this study, a diffusion-controlled combustion model for micro aluminum particle was developed and validated to predict the burning time and capture the evolution of particle size during combustion in environments with multiple oxidizers. Thereafter, the key factors influencing particle combustion were evaluated including particle size, ambient temperature, oxidizer concentration and characteristics of oxide cap. The burning time drops as the oxidizer concentration and the ambient temperature increase, and their influences on burning time become weakened gradually. The effect of oxidizer concentration presents more obvious than ambient temperature. As the number of oxide cap increases from 2 to 5, the burning time rises by 6.9%–27.4%. Then a non-linear empirical equation was proposed to describe the effective oxidizer, which is more accurate than the existing linear correlation, especially for H₂O. Finally, a formula capable of predicting the burning time was proposed and validated, providing a convenient and accurate method for practical application.